Come risolvere il problema Error code: [0x800423f2]

Visualizza lo shadow storage
Vssadmin list shadowstorage

Cancella tutte le snapshot
vssadmin delete shadows /all

Aumenta lo spazio per la snapshot
vssadmin resize shadowstorage /For=C: /On=C: /MaxSize=50GB

Aumentare il timeout delle snapshot
Regedit
HKLMSoftware\Microsoft\Windows NT\CurrentVersion\SPP\CreateTimeout
The default for the timeout period is 10 mins so hopefully doubling this will give enough time to complete the snapshot.
If this isn't present, you will need to manually enter the registry key. It is a DWORD 32-bit key decimal.
Change value to 12000000 (2*10*60*1000 = 20 mins)